Eurotiomycetes is a diverse class of fungi within the phylum Ascomycota, characterized by their ability to produce spores in specialized sac-like structures called asci, often contained in fruiting bodies. Members of this class include both saprophytic species, which decompose organic matter, and medically or industrially important species, such as Aspergillus and Penicillium. They are notable for their adaptability to a wide range of environments, including soil, decaying vegetation, and indoor habitats. Some Eurotiomycetes are opportunistic pathogens in humans and animals, while others are widely used in biotechnology for producing antibiotics, enzymes, and fermented foods. Morphologically, they often form compact, mold-like colonies with conidial spores, making them easily recognizable under the microscope.